Abbreviations: ALK, anaplastic lymphoma receptor tyrosine kinase; ATF4, activating transcription factor 4; BNIP3, BCL2/adenovirus E1B 19kDa interacting protein 3; CNTF, ciliary neurotrophic factor; COX8, cytochrome c oxidase subunit VIII; ConA, concanavalin A; CTSB, cathepsin B; CTSL, cathepsin L; CuB, cucurbitacin B; CYCS, cytochrome c, somatic; EGF, epidermal growth factor; EIF2A, eukaryotic initiation factor 2A, 65kDa; EIF2AK2, eukaryotic translation initiation factor 2-a kinase 2; ER, endoplasmic reticulum; ETC, electron transport chain; FOXO1/3, forkhead box O1/3; HDAC3, histone deacetylase 3; HIF1A, hypoxia inducible factor 1, a subunit (basic helix-loop-helix transcription factor); IL6, interleukin 6; IMM, inner mitochondrial membrane; KDR, kinase insert domain receptor; LMP, lysosomal membrane permeabilization; MAPK1, mitogen-activated protein kinase 1; MAP1LC3A, microtubule-associated protein 1 light chain 3 a; miRNA, microRNA; mitoSTAT3, mitochondrial STAT3; MLS, mitochondrial localization sequence; MMP14, matrix metallopeptidase 14 (membrane-inserted); NDUFA13, NADH dehydrogenase (ubiquinone) 1 a subcomplex, 13; NES, nuclear export signal; NFKB1, nuclear factor of kappa light polypeptide gene enhancer in B-cells 1; NLS, nuclear localization signal; PDGFRB, platelet-derived growth factor receptor, b polypeptide; PRKAA2, protein kinase, AMP-activated, a 2 catalytic subunit; PTPN2, protein tyrosine phosphatase, non-receptor type 2; PTPN6, protein tyrosine phosphatase, non-receptor type 6; PTPN11, protein tyrosine phosphatase, non-receptor type 11; ROS, reactive oxygen species; RTK, receptor tyrosine kinases; SH2, src homology 2; STAT3, signal transducer and activator of transcription 3 (acute-phase response factor); VHL, von Hippel-Lindau tumor suppressor, E3 ubiquitin protein ligase; XPO1, exportin 1.Autophagy is an evolutionarily conserved process in eukaryotes that eliminates harmful components and maintains cellular homeostasis in response to a series of extracellular insults. However, these insults may trigger the downstream signaling of another prominent stress responsive pathway, the STAT3 signaling pathway, which has been implicated in multiple aspects of the autophagic process. Recent reports further indicate that different subcellular localization patterns of STAT3 affect autophagy in various ways. For example, nuclear STAT3 fine-tunes autophagy via the transcriptional regulation of several autophagy-related genes such as BCL2 family members, BECN1, PIK3C3, CTSB, CTSL, PIK3R1, HIF1A, BNIP3, and microRNAs with targets of autophagy modulators. Cytoplasmic STAT3 constitutively inhibits autophagy by sequestering EIF2AK2 as well as by interacting with other autophagy-related signaling molecules such as FOXO1 and FOXO3. Additionally, the mitochondrial translocation of STAT3 suppresses autophagy induced by oxidative stress and may effectively preserve mitochondria from being degraded by mitophagy. Understanding the role of STAT3 signaling in the regulation of autophagy may provide insight into the cla...
The synergism of melatonin and doxorubicin inhibits hepatoma cell growth and induces cell apoptosis.
Background: Multiple primary malignant tumors (MPMTs) are defined as two or more histologically distinct malignancies in one individual, standard treatments for MPMTs are not well established, we aimed to clinical analyze the factors influence the treatment efficacy of MPMTs.Methods: This study retrospectively analyzed 15,321 malignant tumor patients at the Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, China, between March 2006 and June 2016. The survival analysis was performed with SPSS version 22.0 (SPSS Inc., Chicago, IL, USA) with Kaplan-Meier methodology.Results: The prevalence of MPMTs in our study was 1.09% (167/15321), with a male to female ratio of 2.34:1. Specifically, 98 patients harbored synchronous MPMTs, and 69 patients harbored metachronous MPMTs. The most common cancer pairs were digestive-digestive tumor (43 patients, 25.75%), digestive-lung cancer (32 patients, 19.16%), and head & neck-digestive tumor (11 patients, 6.59%). Among patients with synchronous and metachronous first primary cancers, 65.86% received surgery. 33.33% (27/81) of the patients with synchronous MPMTs received simultaneous resection. Of the 69 patients with metachronous MPMTs, 31.88% (22/69) were treated with surgery alone, 62.32% (43/69) received chemotherapy and/or radiotherapy for the first primary tumor, and 44.93% (31/69) received surgery for the other primary tumor. 98.20% (164/167) of patients with MPMTs were effectively followed up, the overall 2- and 5-year survival rates were 54.3% and 31.4%, respectively, with a median survival time of 28.0 months.Conclusions: The early diagnosis of rare MPMTs should not be neglected in patients not only when treated for a primary malignancy but also during long-term follow-up. Effective treatment for MPMTs may yield promising curative effect and warrants further investigation.
During 2010–11, a La Niña condition prevailed in the tropical Pacific. An intermediate coupled model (ICM) is used to demonstrate a real-time forecast of sea surface temperature (SST) evolution during the event. One of the ICM's unique features is an empirical parameterization of the temperature of subsurface water entrained into the mixed layer (Te). This model provided a good prediction, particularly of the "double dip" evolution of SST in 2011 that followed the La Niña event peak in October 2010. Thermocline feedback, explicitly represented by the relationship between Te and sea level in the ICM, is a crucial factor affecting the second cooling in 2011. Large negative Te anomalies were observed to persist in the central equatorial domain during 2010–11, inducing a cold SST anomaly to the east during July–August 2011 and leading to the development of a La Niña condition thereafter.
Necrostatin-1 (Nec-1) inhibits necroptosis by allosterically inhibiting the kinase activity of receptor-interacting protein 1 (RIP1), which plays a critical role in necroptosis. RIP1 is a crucial adaptor kinase involved in the activation of NF-κB, production of reactive oxygen species (ROS) and the phosphorylation of mitogen activated protein kinases (MAPKs). NF-κB, ROS and MAPKs all play important roles in apoptotic signaling. Nec-1 was regarded as having no effect on apoptosis. Here, we report that Nec-1 increased the rate of nuclear condensation and caspases activation induced by a low concentration of shikonin (SHK) in HL60, K562 and primary leukemia cells. siRNA-mediated knockdown of RIP1 significantly enhanced shikonin-induced apoptosis in K562 and HL60 cells. Shikonin treatment alone could slightly inhibit the phosphorylation of ERK1/2 in leukemia cells, and the inhibitory effect on ERK1/2 was significantly augmented by Nec-1. We also found that Nec-1 could inhibit NF-κB p65 translocation to the nucleus at a later stage of SHK treatment. In conclusion, we found that Nec-1 can promote shikonin-induced apoptosis in leukemia cells. The mechanism by which Nec-1 sensitizes shikonin-induced apoptosis appears to be the inhibition of RIP1 kinase-dependent phosphorylation of ERK1/2. To our knowledge, this is the first study to document Nec-1 sensitizes cancer cells to apoptosis.
Autophagy is an evolutionarily conserved survival pathway in eukaryote and is frequently upregulated in cancer cells after chemotherapy or targeted therapy. Thus induction of autophagy has emerged as a drug resistance mechanism. In this study, we found that crizotinib induced a high level of autophagy in lung cancer cells through inhibition of STAT3. Ectopic expression of wild-type or constitutive activated STAT3 significantly suppressed the effect of crizotinib on autophagy. Interestingly, crizotinibmediated inhibition of STAT3 is in a step-wise manner. Firstly it inhibited cytoplasmic STAT3, which leads to the phosphorylation of EIF2A, then inhibited nuclear STAT3, which leads to the downregulation of BCL-2. Cell death induced by crizotinib was greatly enhanced after the inhibition of autophagy by the pharmacological inhibitors or shRNAs against Beclin-1. Moreover, the autophagy inhibitor HCQ significantly augmented the anti-tumor effect of crizotinib in a mouse xenograft model. In conclusion, crizotinib can induce cytoprotective autophagy by suppression of STAT3 in lung cancer cells. Thus, autophagy inhibition represents a promising approach to improve the efficacy of crizotinib in the treatment of targeted lung cancer patients.
Background: Among head and neck squamous cell carcinomas (HNSCCs), hypopharyngeal squamous cell carcinoma (HPSCC) has the worst prognosis. Iron metabolism, which plays a crucial role in tumor progression, is mainly regulated by alterations to genes and post-transcriptional processes. The recent discovery of the N6-methyladenosine (m 6 A) modification has expanded the realm of previously undiscovered post-transcriptional gene regulation mechanisms in eukaryotes. Many studies have demonstrated that m 6 A methylation represents a distinct layer of epigenetic deregulation in carcinogenesis and tumor proliferation. However, the status of m 6 A modification and iron metabolism in HPSCC remains unknown. Methods: Bioinformatics analysis, sample analysis, and transcriptome sequencing were performed to evaluate the correlation between m 6 A modification and iron metabolism. Iron metabolic and cell biological analyses were conducted to evaluate the effect of the m 6 A reader YTHDF1 on HPSCC proliferation and iron metabolism. Transcriptome-wide m 6 A-seq and RIP-seq data were mapped to explore the molecular mechanism of YTHDF1 function in HPSCC. Results: YTHDF1 was found to be closely associated with ferritin levels and intratumoral iron concentrations in HPSCC patients at Sir Run Run Shaw Hospital. YTHDF1 induced-HPSCC tumorigenesis depends on iron metabolism in vivo in vitro . Mechanistically, YTHDF1 methyltransferase domain interacts with the 3'UTR and 5'UTR of TRFC mRNA, then further positively regulates translation of m 6 A-modified TFRC mRNA. Gain-of-function and loss-of-function analyses validated the finding showing that TFRC is a crucial target gene for YTHDF1-mediated increases in iron metabolism. Conclusion: YTHDF1 enhanced TFRC expression in HPSCC through an m 6 A-dependent mechanism. From a therapeutic perspective, targeting YTHDF1 and TFRC-mediated iron metabolism may be a promising strategy for HPSCC.
Aims: To investigate the oncogenic effects of SLC1A5 on gastric cancer development in vitro and in vivo. Methods: The expression level of SLC1A5 was detected in 70 gastric cancer paraffin-embedded tissues by immunohistochemistry and also was detected in gastric cancer cell lines by qRT-PCR and western blotting analysis. The effects of knockdown SLC1A5 were analyzed on cell proliferation, cell cycle, the ability of cell migration and invasion and growth signaling pathway in vitro. By using subcutaneous xenograft mouse, the importance of SLC1A5 expression was assessed for both successful engraftment and growth of gastric cancer cells in vivo. Results: SLC1A5 was up-regulated in gastric cancer tissues and was correlated with malignant features such as deeper local invasion, higher lymph node metastasis, advanced TNM stages and higher Ki-67 expression. Knockdown SLC1A5 in gastric cancer cells suppressed cell proliferation, caused G0/G1 arrest and inhibited cell invasion as well as migration partly by inactivated mTOR/p-70S6K1 signaling pathway in vitro. Furthermore, in vivo experiments indicated that suppression of SLC1A5 could inhibit relative volume of xenografted tumor. Conclusions: Our results suggested that SLC1A5 might be considered as a new biomarker and also as a potential therapeutic target in gastric cancer.
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